Acoustics is the science of sound, including its emission, propagation and reception. By extension, acoustics also refers to all the techniques aimed at improving the quality of sound diffusion in every room. Sound is a vibration that is characterized by its frequency (low or high) and pressure level (strong or weak).

FREQUENCY

Frequency is expressed in Hertz (Hz) and denotes the number of vibrations per second. It can be used to distinguish between low, medium and high-pitched sounds. The human ear is capable of detecting sound at frequencies between 20 and 20,000 Hz.

SOUND PRESSURE LEVEL (DECIBEL DB)

The decibel is a logarithmic measure of the sound pressure level.

REVERBERATION TIME

Reverberation time is a physical criterion that defines a room's acoustic quality. It refers to the length of time required for a sound to drop by 60 dB from its initial level. The longer the reverberation time, the more troublesome the echo and the noisier the room.

It is influenced by several factors, including the size and shape of the room, the quantity, quality and size of the acoustic absorption materials used.

For example, the suspended ceilings in the Tonga® range offer excellent acoustic absorption performance and help significantly reduce the reverberation time, as illustrated in the chart opposite.Example: calculation of the reverberation time before and after fitting Tonga® in a room measuring 270 m3.

ACOUSTIC ABSORPTION

Improving comfort with acoustic correction

Acoustic correction is designed to ensure that the acoustic quality of a room is suitable for its intended purpose.

It can be used to improve the sound quality of a room (such as a classroom or conference hall) for superior comfort or to reduce the sound level of a noisy room to make it more tolerable.

Depending on their intended purpose, not all rooms have the same acoustic correction requirements.

Whether in a concert hall, classroom, open-plan office, individual office, hotel room or hospital room, the ideal acoustic comfort for users depends on the required benefits : improving listening skills, reduction of the sound level of a noisy room, sound insulation from one room to another…

The acoustic absorption principle

The Eurocoustic range of suspended ceilings absorbs sound, which helps reduce resonance, control the room's sound quality and improve acoustic comfort for occupants.

A high absorption coefficient

A material's ability to absorb sound is determined using the Sabin absorption coefficient (α) per frequency over a scale of 0 to 1 (maximum absorption).

The higher a material's absorption coefficient (close to 1), the greater its contribution to the room's acoustic comfort.

Materials are assigned a performance class according to their acoustic absorption coefficient, from Class A (best performance) to E (lowest performance).

Eurocoustic suspended ceilings, such as the Tonga® and Acoustished® range, feature the highest performance rating (Class A), meaning that they significantly improve the acoustic comfort of any room in which they are installed.

LATERAL ATTENUATION

Lateral attenuation is the acoustic insulation between two adjacent rooms. A modular suspended ceiling can be used to achieve this type of acoustic insulation.

The lateral attenuation performance of a ceiling is expressed by a unique index: Dn,f,w, which is measured in the laboratory and expressed in dB.

The higher a ceiling's Dn,f,w, the greater the acoustic insulation between the two rooms, which equates to higher comfort and privacy.

The following conditions must be satisfied for effective lateral attenuation:

The interfaces between the partition and the floor / ceiling must be airtight, such as by adding an Acoustipan® acoustic barrier in the plenum. The use of Acoustipan acoustic barrier in the plenum directly above the partitions can considerably reduce lateral transmissions through the ceiling: for a ceiling composed of Tonga 40 mm tiles, Dn,c,w (C; Ctr) = 28 (-2; -6) dB, and for a ceiling composed of Tonga 40 mm tiles with Acoustipan: Dn,c,w (C; Ctr) = 39 (-2; -7) dB.

There are no accessories in the ceiling that are likely to degrade its performance, such as lighting fixtures and air conditioning vents.

Light diffusion: the higher the %, the more the product will diffuse light in the room. White Tonga® and Acoustished® ceilings diffuse 100% of the light, the best possible performance.

Brightness: the lower the %, the more matte the product's finish, which improves diffusion of the reflected light and prevents the "glare" effect, which is detrimental to visual comfort. The Tonga® and Acoustished® ceilings come with a matte finish (gloss level of 0.75% at an angle of 85° according to NF EN ISO 2813). Combined with Quick-Lock® Ultramatt black grids, they improve visual comfort for the people in the room.

Humidity resistance refers to the ability of a ceiling tile to maintain its structural stability and properties in rooms subject to high humidity levels.

All the ceilings in the Eurocoustic range offer excellent humidity resistance with no sagging regardless of the humidity level.

The oversize ceiling ranges, such as Acoustished® and Acoustished® CV, which are designed for large rooms and spaces (industrial facilities, storage, wineries, etc.), have also been tested and approved for their mechanical resistance. This performance means that the tiles can be garnished with additional insulation solutions, such as Eurolene® panels.

Our range of Corro Plus grids and accessories allows for the installation of ceilings in areas with high humidity levels and also in corrosive environments.

In industrial premises and storage facilities, ceilings are sometimes installed under cold roofs, meaning that they are subject to the airflow and water vapor.

With this type of roof, there may be a movement of air and water vapor created by the difference of temperature between the plenum and the room. Any dust and small air particles passing through the ceiling tiles are likely to build up and leave marks on the visible side of the tiles (filter effect). Water vapor may sometimes condense on the back of the tiles on contact with the cold air in the plenum (condensation).

The solution involves using a vapor barrier to block the airflow and water vapor.

The Eurocoustic ceilings in the Acoustished® CV range are equipped with an aluminum sheet technology to prevent the airflow and water vapor.

Ceilings have a direct effect on a room's visual comfort. Their esthetic appearance is important.

Eurocoustic ceiling tiles are available with different decorative veils, including white, black, grey and other colors, as well as the Boreal® painted finish and technical veils featuring other finishes (including a reinforcement glass grid for Acoustichoc®). The Eurocolors range adds a stylish touch to the Tonga® range with a wide variety of colors and patterns.

Tiles are also available with several types of edge - A (straight) and E (bevelled) - so that users can customize and adapt the ceiling's appearance.

In some types of room, suspended ceilings are frequently cleaned, involving different cleaning methods for various types of tasks.

The ceilings in the Eurocoustic range do not retain dust, which makes them easier to clean and extends their service lives. They can be cleaned using a light brush or vacuum cleaner.

The Tonga® Ultra Clean range can also be cleaned with a wet sponge (with or without detergent), dry / wet steam + dry cloth. As such, it is suited to rooms with demanding requirements, including kitchens, collective dining areas and laboratories. The Tonga® Ultra Clean HP range is also compatible with high-pressure cleaning.

Finally, the ceilings in the Clini’Safe® range resist the most widespread disinfectants in hospitals (with a base of hydrogen peroxide, chlorine dioxide and glutaraldehyde).